Posts Tagged acoustical panels
For anyone new to the world of acoustics, there is a multitude of terms, coefficients and numbers that are thrown around. This flood of information can seem intimidating, especially to beginners. In this series, acoustician Cameron Girard of Acoustics First® hopes to help you distinguish between what’s useful and what’s not.
Part 2: How Mounting in Testing Affects Sound Absorption Data
As I discussed in my previous article, the best way to compare the performance of sound absorbing panels is by referencing the Sound Absorption Coefficient (SAC) and Noise Reduction Coefficient (NRC). However, these coefficients are often used as marketing tools. Be on the lookout for companies that list absorption coefficients and NRCs without mention of a particular testing standard or mounting method. It’s vital to check for this information, as direct comparisons to competitors and other materials can only be made if their testing procedures are the same.
The sound absorption of a material that covers a flat surface not only depends on the physical qualities of the material but also on how the material is mounted during installation. The mountings specified in laboratory tests are intended to simulate conditions that exist in normal use, such as direct wall mounting and installation into a ceiling grid.
Many materials for treatment of walls or ceiling are tested using what is called Type ”A” mounting. Type ”A” mounting means the test specimen was placed directly on the test surface of the reverberation chamber. Lay-in ceiling tiles, on the other hand, are often tested using ”E400” mounting. The ”E” designates a sealed air space behind the specimen (simulating the air gap between a dropped tile ceiling and the structural ceiling) and the number after the ”E” is the depth of the airspace in millimeters. The airspace behind the acoustic material affects the sound absorption by acting as a bass trap. The deeper the cavity behind the panels is, the lower the fundamental of the “trapped” frequencies will be.
To see what this look like in terms of actual numbers, let’s take a look at how different mounting methods effect the sound absorption coefficients of Acoustics First’s HiPer® Panel (a low-profile, composite absorber/diffuser panel).
Since the HiPer® Panel can be used effectively in multiple applications; we had it tested in accordance to the two most-common mounting procedures, Type E-400 and Type A. The results of the laboratory tests are as follows:
Sound Absorption Coefficients
|1″ HiPer® Panel||1″||E-400||0.43||0.28||0.51||0.76||0.99||1.10||0.65|
|1″ HiPer® Panel||1″||A||0.09||0.28||0.78||0.75||0.94||0.85||0.70|
As you can see from the chart, the sound absorption coefficient at 125 Hz varies greatly between E-400 mounting (SAC of .43) and Type-A mounting (SAC of .09). If mounting the HiPer® Panel in a ceiling grid, with a sizable airspace, you can expect significant low-frequency absorption, but mounting it on a wall (Type-A) will result in much less absorption at 125Hz.
Other mounting methods are available, but are not used as frequently. Here are some of the basic mounting designations (See ASTM E795 for more information.)
Type A mounting – Test specimen laid directly against the test surface (wall panel on drywall).
Type B mounting – Test specimen cemented directly against the test surface. Type B mounting is intended to simulate acoustical ceiling tiles or other sound-absorptive products adhered to a hard surface with an adhesive.
Type C Mounting—Test specimen comprising sound-absorptive material behind a perforated, expanded, open facing or other porous material.
Type D Mounting—Test specimen mounted on wood furring strips.
Type E Mounting—Test specimen mounted with an air space behind it (dropped tile ceiling).
As we’ve discussed, acoustical data can vary greatly depending on the mounting method used during testing. Acoustics First tries to include as much information about testing procedures as possible, because we feel an informed client makes the best client.
Contact Acoustics First for your all your sound control needs!
There is a saying in our industry: When it comes to designing a space, acoustic consultants are blind and architects are deaf. In reality, it is in both parties best interest to consider the other side when designing a space, so visual form meets acoustic functionality.
Let’s be real, standard acoustic treatment is far from sexy. Typical 2’x4’ panels, while fully functional, don’t present the architects with much in terms of visual interest. This is where Acoustics First can supplement the design goals of the architect/interior designer with our technical expertise to find a custom solution that sounds and looks great.
Recently, Acoustics First® was asked to provide the custom panels for the cafeteria at Kramer Middle School in Washington DC. It was settled that hexagonal ToneTiles™ would be suspended as clouds in a geometric pattern around the ceiling. The resulting “honeycomb” effect is not only visually appealing, but the treatments effectively cut down the overall reverberation; increasing speech intelligibility and making the space more comfortable for a variety of activities.
Acoustics First® enjoys the inherent challenge in making these custom panels a success. We have plenty of experience in fulfilling the design goals of architects and interior designers. Interested in seeing more of these custom projects?
Visit http://acousticsfirst.com/installations-education-school-museum.htm to see some more examples.
Feel free to give Acoustics First® a call to discuss your custom treatment needs!
Season’s Greetings from Acoustics First!
Acoustics First would like to offer this Do-It-Yourself gift idea to all of our readers this year.
If you’ve got a creative painting habit, give a customized gift that not only shows your creative talents, but also helps to improve the sound of the room!
Above is a festive holiday painting on one of our 1’x2′ Tone Tiles™.
Want to go a little bigger? We also have 2’x3′ Tone Tiles™ in Stock.
A Second Idea is to get a photo printed on a Tone Tile™.
How about “posting” that photo to the “wall” of your living room, and have a great conversation piece as well as improved acoustics – at the same time !
Season’s Greetings and Happy Gift Giving!
– Acoustics First
* Don’t forget to ask your local printer if they have flatbed printing capabilities.
Sometimes at Acoustics First we get a call from someone who is so knowledgeable that we can’t help but be tickled that they called us to help them. We received one such phone call from Pete Heskin at Barrett’s Technology Solutions in Naperville, IL.
Pete and his team were putting together an acoustic treatment for a listening room at their facility and wanted the room’s acoustics to really showcase their lineup of high-end audiophile speakers. No joke here – these guys have over 50 years of experience in the audio industry – and they keep on the bleeding edge of audio and video. This treatment is serious acoustic business – and these are some of the most discriminating ears in audio.
Happy Easter guys!
In keeping with their high-standards and cutting edge approach, they were looking for an acoustic treatment that is as visually stunning as it is capable of treating a room containing some of the world’s greatest sound sources. As you can see, the results are simple and elegant.
The room contains an array of Sonora® panels, Silent Pictures® and clusters of ArtDiffusor® Model D‘s to make this space sound as good as it looks. (While all of their gear makes the gear junkies at Acoustics First drool…)
So, if you find yourself near Chicago, or on a “Wayne’s World” pilgrimage, stop into Barrett’s – and if you fancy yourself an audiophile – put your money where your ears are, and hear how discriminating ears listen to music…
… No Stairway to Heaven.
Posted by Acoustics First in Absorption, Auditorium, Broadcast Facilities, Diffusion, DIY, Home Entertainment, Home Theater, HOW TO, Media Room, Multipurpose Rooms, Music Rehearsal Spaces, Music Tracking Room, Product Applications, Products, Recording Facilities, Recording Studio, Restaurants, Studio Control Room, Teleconferencing, Theater, Vocal Booth, Voice Over, Worship Facilities on June 20, 2013
Getting more out of your back wall diffuser array with a simple hanging DIY array/bass trap.
One of the big “back wall” questions people have is “If I have a large diffuser array, how can I get the bass trapping I need?” A great answer to this question is to turn the entire array into a hanging bass absorber. If you are already planning on getting diffusion for your back wall, here is a great way to use that wall space for more than just diffusion.
Stuff you need:
- 4’x 8’ sheet of 3/4” Plywood
- 32 sq/ft of 4” Cutting Wedge® Classic Foam (Or similar absorber)
- 8 x Art Diffusers® – Model C (or Model F, Quadrapyramid™, or other comparable diffuser)
- 2 x IsoHangers
- 2 x Heavy rings (Think big Curtain Rings or Hanging Wire will also work)
- 2x Closet Rod/Shelf Brackets
- 2 x 7/8” wood screws and fender washers
- Construction Adhesive (Make sure it’s safe for Foam)
- Screw the two IsoHangers to the plywood, using a fender washer on each screw. These should be about an inch in from each end -drill small pilot holes first. (These will be used to hang the panel, this side will be designated as the back from here on out.)
- Use Construction adhesive to attach the Cutting Wedge® Foam to the back of the panel in a checkerboard pattern (each panel 90° rotated from adjacent)
- Use Construction adhesive again to attach the 8 Diffusers to the front of the Plywood (Follow the installation instructions for adhesive placement)
- Attach the Rings or Wire to the free end of the IsoHangers.
What you have created is a hanging panel that will diffuse mid-high frequencies and trap the lows. The hanging mass absorbs low frequency energy by moving slightly when pushed by the energy of the Low frequency Waves. The rear facing fiberglass also absorbs low frequencies by dampening the panel, but it also absorbs any of the waves that happen to get trapped behind the panel.
Hanging the Diffuser/Trap Assembly
- Measure and attach the Closet Brackets to the Wall – Use appropriate anchors! If you have standard or double wall construction without Resilient Channels, use the studs – The IsoHangers will keep vibrations from transmitting through the wall.
- Hang the panel on the Closet Brackets using the rings/wire with the Diffusers facing you and that’s it!
This simple DIY project is provided as a way for our customers to learn better ways to use our products and get more value out of the products they buy. For those customers who are planning on purchasing diffusers to make an array, or maybe already have an array and are looking to try a new configuration – this project may be what you’re looking for.
A little History…
If you embark on this little construction project, you will be constructing studio elements that have remained basically unchanged since at least the early 1970’s. Hanging plywood wrapped in studio foam or fiberglass has been used “behind the curtains” of many of the top studios for effective bass control for over 40 years – just no one has ever seen it, as it has been hidden in walls; masked as a false wall of fabric stretched across wooden louvers!
Acoustics First Corporation supplies acoustical panels and soundproofing materials to control sound and eliminate noise in commercial, residential, government, and institutional applications worldwide. Products include the patented Art Diffusor®, sound absorbers, noise barriers, acoustical fabrics and accessories. Acoustics First® products are sold for O.E.M applications, direct, and through dealers. For more information on acoustical materials and their application, please visit www.AcousticsFirst.com or call Toll Free 1-888-765-2900 (US & Canada).